GRUBEL, H.; WALKER, M. The dominance of producers services in the U.S. economy. PSL Quarterly Review, [S. l.], v. 44, n. 176, 2013. DOI: 10.13133/2037-3643/10936. Disponível em: https://rosa.uniroma1.it/rosa04/psl_quarterly_review/article/view/10936. Acesso em: 23 jul. 2024.